1. Field of the Invention
This invention relates to a detergent composition, and, more particularly, to a detergent composition which is low irritant, giving remarkably reduced damage to hair and skin. The composition has excellent foaming power and detergency, and yet is easily rinsed out and at the same time provides an agreeable sensation to the hands during use.
2. Description of the Background Art
Because of the increased awareness concerning safety of the human body in recent years, a number of attempts have been undertaken to achieve mildness to the skin in the manufacture of laundry detergents, dishwashing detergents, detergents for use with household articles, as well as those for the hair and the body. An example of such attempts is to adjust the pH of detergent compositions to a weakly acidic range, i.e., pH 5-6, which is near the pH of the human skin, thereby obtaining mildness to the skin. Another example is the use of a low irritant detergent base as a major detergent component. Amino acid type or alkylphosphate type surface active agents are used as low irritant detergent bases for this purpose (Japanese Patent Publication Nos. 40125/1975, 426023/1976, 9033/1980, and 27319/1983). Although these surface active agents are low irritant, they have drawbacks such as insufficient foaming power and detergency, poor solubility, and the like when used alone. Sodium alkylbenzenesulfonates have conventionally been used as a detergent base for dishwashing detergent compositions. Although they have excellent detergency, their strong defatting action is liable to cause skin roughening.
For these reasons, sodium alkylethoxysulfates which are less irritant have currently been used as a detergent base for dishwashing detergent compositions. Their use in combination with tertiary amine oxides, higher fatty acid diethanolamides, etc., as auxiliary surface active agents, has promoted various performances, providing dishwashing detergent compositions with reduced irritation to the skin.
In spite of these efforts for producing detergent compositions which are less irritant and mild to the skin, the level of improvement hitherto achieved is not yet satisfactory.
Alkyl glycosides, which are sugar-derived surface active agents, are low irritant, nonionic surface active agents. Even though nonionic in nature, alkyl glycosides not only produce stable foams by themselves but also are known to act as foam stabilizers for anionic surface active agents. Because of this, a great deal of attention has been given to alkyl glycosides in recent years. Japanese Patent Laid-open No. 104625/1983, for example, discloses a foaming surfactant composition comprising an anionic surface active agent and an alkyl glycoside. Japanese Patent Laid-open No. 74999/1987 describes a low irritant liquid detergent composition for kitchen use having superior foaming power and detergency which comprises an alkyl glycoside, an anionic surface active agent, and a fatty acid diethanolamide. These detergent compositions, although exhibiting performances better than conventional detergent compositions using polyoxyethylenealkyl ethers as a major component, are not yet satisfactory, especially in their rinse-out performance and in the sensation which they impart to the hands during washing.
In view of this situation, the present inventors have conducted extensive studies to make the best use of the superior characteristics of alkyl glycosides. As a result, the present inventors found that use of a specific type of dicarboxylic acid surface active agents together with alkyl glycoside compounds lessened the irritation to the skin, promoted detergency and foaming power, and at the same time brought about improved rinse-out performance and better feeling to the hands during washing. Such a finding has led to the completion of the present invention.